Professional CodeIgniter

Chapter 5: Building a Shopping Cart

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You ’ re going to combine the two approaches. Your more sensitive data are going to go into PHP sessions.

Other data, like a flag that indicates whether there are any items in the Shopping Cart, will go into the

CodeIgniter session.

Before going any further, it ’ s a good idea to review what the expectations are concerning the

Shopping Cart.

The first thing to notice when reviewing the diagrams is that you need to change the “ buy now ” links

in your views to “ add to cart. ” If you recall, early in the diagramming process, Claudia asked you

to change the potentially confusing “ buy now ” links with a more accurate “ add to cart ”. Making this

change is easy enough, implemented with a simple search and replace in any text editor.

The second thing is that the process of adding a product to a shopping cart doesn ’ t really involve a view.

Instead, it can simply use a status message to provide the user with visual confirmation, as pictured in

Figure 5 - 1.

Figure 5 - 1

This status message can be achieved with very little effort in the controller cart() function.

Finally, the third thing to consider (and this is also illustrated in Figure 5 - 1 ) is that once a user has added

items to her cart, a third navigation option (called “ view cart ” ) is dynamically added to the main

navigation. When the user clicks this link, she can view and manipulate items in her Shopping Cart, as

illustrated in Figure 5 - 2.